vicky, where are you from?
there are many different ways to finance a PhD - just about as many as PhD students...
having your fees paid for you is already half way there.
to add to that, you can apply to your university's research fund; to the research council; to your home country, if you're not British; to the international federation of university women; and many more places.
you can also get try to get a loan from a bank, or assistance from your parents.
and you can get a little job to make up for the shortfall. don't worry - whereas there are some lucky people who are fully funded, most everyone does work a little on the side. there are advantages to that, too (i.e. time structures)